To buy a 'new to us' car...refi?

This is my first post, and I tend to over-explain, but would like an informed opinion.

I am trying to purchase a used car. Here's a bit of history. I started getting 'credit smart' about two years ago, and am pleased with my progress. freecreditreport.com (Equifax) lists my PLUS score, which I guess is similar to FICO, currently at 677, though I've been as high as 707 (before maxing out cc's, which are paid back down now, I'm just waiting for that information to reach the CRA's). My wife is sitting in the 640 range. In the last two years, we've bought (and then almost immediately refinanced the VERY high rate to a plain very high rate) a truck, and a house. I have 23 hard inquiries from 'rate shopping', as I was told if done within a certain time frame, they would only count as one (this isn't true in my experience, BTW). My payment history, though only 1-2 years old, depending on the account, is spotless; OK's across the board. My problems seem to be lack of history (apparently people like seeing three years), my credit limits (I have three major cards, $300-$1000 limits) and one card through the Military Exchange is near maxed ($6000 of $6500 available), and then all of the inquiries. My strengths are timely payments (including the house, which I've had a year), job (been in the military 6 years), aside from the one card most balances are at or near $0, and no collections, judgments, BK's, etc.

So, here's my question(s): Should I look to refinance my truck to lower my D/E ratio prior to looking at getting a used car? The rate is high (14.5%) because at the time I had next to no history, and my wife's credit was below 600, so I would really like to do a refi at a better rate, but am concerned that it will hurt our chances at getting a second vehicle. Last, but not least, with my history, I can't do a bunch of inquiries again to shop for a good rate. What are some tried and true places to go for folks in my situation? I've heard University CU, Navy Federal Credit Union (I'm Coast Guard). Can I provide them my credit report to avoid an inquiry? Are any of them honest enough to listen to my plight and tell me straight-up if I've got a good shot at a decent rate wihtout running a bureau? We don't HAVE to have a second vehicle right now, but it would make life a lot easier.

Again, I'm very detail oriented, but thanks for reading, and thanks in advance for any advice!

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